Synthesis and investigation of the properties of α-(6-methyl-2-benzothiazolyl)-α-phenyl-β-(2,6-dinitrophenyl)hydrazyl, α-(2-methyl-6-benzothiazolyl)-α-phenyl-β-(2,6-dinitrophenyl)-hydrazyl,and the correspondinghydrazines

-(6-Methyl-2-benzothiazolyl)--phenyl--(2,6-dinitrophenyl)hydrazyl and -(2-methyl-6-benzothiazolyl)--phenyl--(2,6-dinitrophenyl)hydrazyl and their corresponding hydrazines were synthesized. The properties of the compounds obtained were investigated by IR, UV, and visible spectroscopy. Their complexing ability was studied by an optical method and from their electrical conductivity. The ESR spectra of the radicals were recorded. The limiting currents and reduction potentials of the hydrazines on a dropping mercury electrode were found. The charge and spin densities of the compounds were calculated by means of the Hückel MO and MacLachlan methods. It was demonstrated that the hydrazines form unstable charge-transfer complexes in benzene—piperidine solutions; the characteristics of these complexes depend on the structure of the RRN-NH-hydrazine residue.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1484–1490, November, 1971.     

Asymptotic Research of Nonlinear Wave Processes in Saturated Porous Media

The problem of nonlinear wave dynamics of a fluid-saturated porous medium is investigated. The mathematical model proposed is based on the classical Frenkel--Biot--Nikolaevskiy theory concerning elastic wave propagation and includes mass, momentum, energy conservation laws, as well as rheological and thermodynamic relations. The model describes nonlinear, dispersive, and dissipative medium. To solve the system of differential equations, an asymptotic modified two-scales method is developed and a Cauchy problem for initial equations system is transformed to a Cauchy problem for nonlinear generalized Korteweg--de Vries--Burgers equation for modulated quick wave amplitudes and an inhomogeneous set of equations for slow background motion. Stationary solutions of the derived evolutionary equation that have been constructed numerically reflect different regimes of elastic wave attenuation: diffusive, oscillating, and soliton-like.     

Throughput optimization in robotic cells with input and output machine buffers: A comparative study of two key models

We consider the problem of scheduling operations in a robotic cell processing a single part type. Each machine in the cell has a one-unit input buffer and a one-unit output buffer. The machines and buffers are served by one single gripper robot. The domain considered is free-pickup cells with additive inter-machine travel time. The processing constraints specify the cell to be a flow shop. The objective is to find a cyclic sequence of robot moves that minimizes the long-run average time to produce a part or, equivalently, maximizes throughput. Bufferless robotic cells have been studied extensively in the literature. However, the few studies of robotic cells with output buffers at each machine have shown that the throughput can be improved by such a configuration. We show that there is no throughput advantage in providing machine input buffers in addition to output buffers. The equivalence in throughput between the two models has significant practical implications, since the cost of providing additional buffers at each machine is substantial.     

ChemInform Abstract: Single-Crystal and Powder Neutron Diffraction Study of the FexMn1-xS Solid Solutions.

Single crystals of the α-MnS-based Fe_xMn_1-xS (x = 0-0.3) solid solutions are prepared and shown to be new Mott materials with the rock salt structure.